A publication, EP-A-0360354 (U.S. Pat. No. 5,042,428 of Aug. 27, 1991), discloses a sensor apparatus for determining the position of an object, such as a teat, in a space. The sensor is provided with a transmitter element or elements and a receiving element or elements which receive a ray or beam of rays reflected from the object. A directional element directs the ray or beam from the transmitter element to different areas in the space or directs reflections to the receiving element, or both. EP-A-0360354 also discloses a method for determining the position of an object in space which uses the above apparatus which includes evaluating reflections by means of an evaluation device which determines the location of the object relative to the sensor apparatus. In accordance with said publication, for the purpose of scanning the space by means of a laser beam, the housing of the sensor apparatus with the transmitter and receiver elements fixedly arranged therein is pivoted in a reciprocating manner by motor drive through the desired scanning angle.